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http://dx.doi.org/10.5573/JSTS.2015.15.3.349

A Fully-Differential Correlated Doubling Sampling Readout Circuit for Mutual-capacitance Touch Screens  

Kwon, Kihyun (school of electrical and computer engineering, Ulsan National Institute of Science and Technology)
Kim, Sung-Woo (school of electrical and computer engineering, Ulsan National Institute of Science and Technology)
Bien, Franklin (school of electrical and computer engineering, Ulsan National Institute of Science and Technology)
Kim, Jae Joon (school of electrical and computer engineering, Ulsan National Institute of Science and Technology)
Publication Information
JSTS:Journal of Semiconductor Technology and Science / v.15, no.3, 2015 , pp. 349-355 More about this Journal
Abstract
A fully-differential touch-screen sensing architecture is presented to improve noise immunity and also support most multi-touch events minimizing the number of amplifiers and their silicon area. A correlated double sampling function is incorporated to reduce DC offset and low-frequency noises, and a stabilizer circuit is also embedded to minimize inherent transient fluctuations. A prototype of the proposed readout circuit was fabricated in a $0.18{\mu}m$ CMOS process and its differential operation in response to various touch events was experimentally verified. With a 3.3 V supply, the current dissipation was 3.4 mA at normal operation and $140{\mu}A$ in standby mode.
Keywords
Sensor interface; readout circuit; Touch screen; differential; mutual capacitance;
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1 Y. Hu, et al., "3D gesture-sensing system for interactive displays based on extended-range capacitive sensing," IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers, pp. 212-213, Feb., 2014.
2 J.-H. Yang,, et al, "A Noise-Immune High-Speed Readout Circuit for In-Cell Touch Screen Panels," IEEE Trans. Circuits Syst. I, Reg. Papers., 60, (7), pp. 1800-1809, 2013.   DOI   ScienceOn
3 J.-E. Park, D.-H. Lim and D.-K. Jeong, "A reconfigurable 40-to-67 dB SNR, 50-to-6400 Hz frame-rate, column-parallel readout IC for capacitive touch-screen panels," IEEE J. Solid- State Circuits, vol. 49, no. 10, pp. 2305-2318, Oct., 2014.   DOI   ScienceOn
4 J.-H. Yang, et al., "A highly noise-immune touch controller using filtered-delta-integration and a charge-interpolation technique for 10.1-inch capacitive touch-screen panels," IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers, pp. 390- 391, Feb., 2013.
5 H. Shin, et al., "A 55dB SNR with 240Hz frame scan rate mutual capacitor 30x24 touch-screen panel read-out IC using code-division multiple sensing technique," IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers, pp. 388-389, Feb., 2013.
6 D.-H., Lim, J.-E. Park, and D.-K. Jeong, "A lownoise differential front-end and its controller for capacitive touch screen panels," Proc. 38th Eur. Solid-State Circuits Conf., pp. 237-240, Sept., 2012.
7 I.-S. Yang and O.-K. Kwon, "A touch controller using differential sensing method for on-cell capacitive touch screen panel systems," IEEE Trans. Consumer Electron., 57, (3), pp. 1027-1032, May, 2011.   DOI   ScienceOn
8 C. C. Enz and G. C. Temes "Circuit technique for reducing the effects of op-amp imperfections: autozeroing, correlated double sampling, and chopper stabilization," Proc. of the IEEE, vol. 84, no. 11, pp. 1584-1614, Nov., 1996.
9 K. Lim, K.-S Jung, C.-S Jang, J.-S. Baek and I,-B. Kang, "A Fast and Energy Efficient Single-Chip Touch Controller for Tablet Touch Applications," Journal of Display Technology, vol. 9, no. 7, pp. 520-526, 2013.   DOI   ScienceOn